Portable cradle

ABSTRACT

Described is a portable cradle which includes a removable planar surface, a base and a plurality of vertical support members removably coupled to the base and supporting the planar surface above the base. Each vertical support member includes a biasing member urging the planar member upward away from the base with a total biasing force applied to the planar member being selected based on property of materials to be supported on the planar surface so that a position of an upper surface of the supported materials remains substantially constant as a quantity of materials supported on the planar surface is changed.

FIELD OF THE INVENTION

[0001] The present invention relates to portable devices that facilitatedispensing of materials. More specifically, the present inventionrelates to portable cradle devices with a feed mechanism that dispensevarious materials.

BACKGROUND INFORMATION

[0002] Many types of construction materials are used as slabs or sheets,that can be used directly as in the case of pre-shaped tiles and bricks,or can be finished and then used, as in the case of sheet rock, concreteslabs and the like. Typically, these materials are supplied to the worksite in stacks, such that the sheets of material are placed one on topof the other, and possibly bound together, so that large numbers of thematerial elements may be moved at one time. When the materials are used,the stacks are moved near the location where they are needed, and thematerial elements are removed from the stack one by one.

[0003] As the sheet like construction materials are removed from thestack, the height of the stack is reduced. Since the construction workerremoves the materials from the top of the stack, the topmost elementthat is presented to the worker for removal is not in a fixed position.When the stack is first started, the element being presented may be at agreat height, at the top of the original stack. When the stack is almostused up, the element being presented is low, near a surface where thestack has been deposited, such as on the ground.

[0004] This method of stacking elements of construction materials is notsatisfactory, because it forces the worker to reach up for the materialsat first, and to reach further and further down as the stack ofmaterials is used. This process is not efficient, because the worker hasto constantly reach for the materials in a different location. Theprocess may be also unsafe, because the worker at some times has toreach up and lower to a working height the possibly heavy materials, andat other times must lift the materials up from near the ground. Backinjuries may ensue from repeatedly lifting the heavy constructionelements, while the materials may be dropped when removed from the topof a high stack, causing possible injury to the worker or damage to thematerials.

[0005] The problem may be somewhat alleviated by using materials boundin smaller stacks, so that the distance between the top and bottom ofthe stack is not great. However, it is much more efficient to move theconstruction materials in larger stacks, so that fewer trips to the worklocation are necessary to complete the work. In particular, if forklifts or other mechanized equipment is used to move the materials, thelarger the stack that can be brought to individual workers, the moreefficient the process becomes.

SUMMARY OF THE INVENTION

[0006] The present invention relates to a portable cradle which includesa removable planar surface, a base and a plurality of vertical supportmembers removably coupled to the base and supporting the planar surfaceabove the base. Each vertical support member includes a biasing memberurging the planar member upward away from the base with a total biasingforce applied to the planar member being selected based on property ofmaterials to be supported on the planar surface so that a position of anupper surface of the supported materials remains substantially constantas a quantity of materials supported on the planar surface is changed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007]FIG. 1a shows a perspective view of an exemplary embodiment of thecradle according to the present invention;

[0008]FIG. 1b shows another exemplary embodiment of the cradle accordingto the present invention;

[0009]FIG. 2a shows a side elevation view of the embodiment shown inFIG. 1a;

[0010]FIG. 2b shows a side elevation view of the embodiment shown inFIG. 1b;

[0011]FIG. 3a shows a top plan view of the embodiment shown in FIG. 1a;

[0012]FIG. 3b shows a top plan view of the embodiment shown in FIG. 1ahaving female attaching members;

[0013]FIG. 4 shows a sectional view on line IV-IV of FIGS. 2a and 2 b ofan embodiment of the support and spring structure;

[0014]FIG. 5 shows a sectional view on line V-V of FIGS. 2a and 2 b ofan embodiment of the connection between a support structure and a planarsurface;

[0015]FIG. 6 shows a perspective view showing a detail of mountingblocks on a base according to an embodiment of the present invention;

[0016]FIG. 7 shows a top view showing a first storage configuration ofthe cradle according to the present invention; and

[0017]FIG. 8 shows a top view showing a second storage configuration ofthe cradle according to the present invention.

DETAILED DESCRIPTION

[0018] The present invention may be further understood with reference tothe following description and the appended drawings, wherein likeelements are referred to with the same reference numerals.

[0019] The cradle according to embodiments of the present invention maybe utilized to hold stacks of materials (e.g., sheet-like constructionmaterials) near the point of use of those materials. The exemplarycradle presents a topmost one of the elements in the stack at asubstantially constant height, so that the worker using the materialscan reach for the materials at a nearly constant, convenient heightabove the ground. The worker does not have to reach up to take theelements when the stack is full, and does not have to bend over to pickup the material elements when the stack is nearly used up. Thus, theworker may incur fewer injuries due to lifting and may work in a moreefficient manner. Large stacks can be used, while the top most elementin the stack is always presented at a convenient location.

[0020]FIG. 1a shows an exemplary embodiment of the cradle according tothe present invention. Cradle 100 includes a base 102 that provides ananchoring point on the ground for the rest of the cradle 100. A supportmechanism 109 is provided to position planar surface 106 relative to thebase 102. Planar surface 106 receives the materials 200 (e.g.,construction materials), and is movable in the direction shown by arrows“A” with respect to base 102. Support mechanism 109 provides a guide tocontrol the movement of planar surface 106, so that it can move only ina direction substantially perpendicular to base 102. A system to resistdisplacement of planar surface 102 from a preferred distance “d” frombase 102 is also provided by support mechanism 109. This system appliesa restoring force to planar surface 106, that opposes the weight ofconstruction elements 200 deposited on the planar surface 106.

[0021] In the exemplary embodiment shown in FIG. 1a, the supportmechanism 109 includes several support members 104 that are secured tobase 102, and extend substantially perpendicularly therefrom. Supports104 and base 102 form a structural frame for cradle 100. For example,for a rectangular base 102, there may be four supports 104 placed at thecorners of base 102. Alternatively, a different shape of the base 102 orplanar surface 106 may require a different configuration of supports104. Supports 104 may include guides 108 that are designed to direct themovement of planar surface 106 in a desired direction. Guides 108 mayhave a shape complementary to corners 111, to permit planar surface 106to move in a direction along arrows “A”, substantially perpendicular tobase 102.

[0022]FIG. 1b shows another exemplary embodiment of the cradle 100according to the present invention which is similar to the embodimentshown in FIG. 1a. The cradle 100 has a plurality (e.g., three or four)moving arrangements, such as wheels 230, 232. The moving arrangementsallows the worker easily move heavy loads of materials 200. In addition,the moving arrangements may have a braking mechanism (not shown). Thebraking mechanism allows the worker to fix the cradle 100 at aparticular location, thus preventing the cradle 100 from incidentallymoving from that fixed location.

[0023] Also, the material 200 may be a different shapes. For example,the material 200 may be a shape of the surface 106 (as shown in FIG.2a). Alternately, the material 200 may be of a smaller shape and placedin the middle of the surface 106 (as shown in FIG. 1a). Those skilled inthe art would understand that materials 200 may come in different shapesand sizes and that the cradle 100 may be adjusted to accommodate thesesshapes and sizes. For example, to accommodate the smaller shapematerials 200 (as a shown in FIG. 1a), a frame (not shown) may beattached to the surface 106 which would prevent the materials 200 fromshifting.

[0024] As shown in FIGS. 1a, 1 b, 2 a and 2 b, support mechanism 109 mayalso include resilient/biasing elements such as springs 110, used tourge the planar surface 106 to a desired height “d” from base 102.Springs 110 may be associated with the supports 104, or alternativelymay be separate. In the exemplary embodiment shown, there is a spring110 for each support 104. However, the number of springs 110 andsupports 104 does not have to be the same. In the exemplary embodiment,springs 110 are located between the base 102 and planar surface 106. Theneutral extension of springs 110, meaning the extension at which noforce is exerted, corresponds to the desired height “d”. When a weightsuch as stack 200 is placed in planar surface 106, springs 110 arecompressed, and tend to resist the displacement of planar surface 106.Since the resisting force exerted by a spring is proportional to itscompression, the more planar surface 106 is displaced, the greater theforce opposing such displacement is generated by springs 110.

[0025] By carefully selecting the size and spring constant of springs110, it is possible to control the displacement of planar surface 106such that topmost element 202 on stack 200 will always be at or near theheight “d” from base 102. For example, when the cradle 100 is empty, theweight of planar surface 106 will balance the spring force at height“d”. When a full stack is added, the additional weight compressessprings 110 until topmost element 202 is approximately at a height “d”,while planar surface 106 is lower. As the elements of constructionmaterial are removed from the top of stack 200, the reduced weightcompresses springs 110 less, and planar surface 106 is pushed upwards,such that the new topmost element is now approximately at a height “d”above base 102. It should be apparent to one skilled in the art that thesame result may be obtained by using springs under tension rather thanunder compression, for example simply by connecting the springs to thetops of supports 104 rather than to base 102. A feed mechanism for theconstruction elements is thus provided, that places the topmost elementof the stack at a constant height.

[0026] The exemplary embodiment shown provides the advantage that planarsurface 106 is to a certain extent self leveling. Springs 110 arelocated at the corners, and if a weight is placed near a corner ratherthan near the center of planar surface 106, the spring nearest to theweight will be compressed the most, causing a greater restoring forcethat opposes further compression of that spring. The corner where theweight was added thus drops only a small distance, before furtherdisplacement is stopped by the spring.

[0027] Elements of the exemplary embodiment of the present invention arefurther described with reference to FIG. 4. A detail of the supportmechanism 109 is shown, as a cross section view taken on line IV-IV ofFIGS. 2a and 2 b. One of supports 104 is shown, in this example having astructural portion with an L shaped cross section which resistsbuckling, and provides stability to the structure. In this example, thefour L shaped supports 104, together with base 102, form a rigid framethat keeps the movement of planar surface 106 constrained to the desireddirection.

[0028] The support mechanism 109 of the exemplary embodiment includes aspring guide 112 that may be attached to support member 104. Springguide 112 surrounds a portion of the perimeter of spring 110, and thusprevents it from buckling or being displaced. In this exemplaryembodiment, spring guide 112 forms an internal channel, but does notcompletely surround spring 110, so that a connection with planar surface106 may be made, as will be described below. However, otherconfigurations of spring guide 112 may be devised, which may surroundspring 110 to a greater or lesser extent. In the configuration shown inFIG. 4, spring guide 112 has a circular cross section that extends forslightly more than 180 degrees, so that spring 110 cannot fall outthrough the opening defined by edges 120. In this configuration, spring110 is not attached to spring guide 112, and is retained by gravitywithin channel 122 defined by the guide 112.

[0029] Planar surface 106 may have extensions 114 that are shaped to fitin guides 108 of the support mechanism 109. In the exemplary embodimentshown in FIG. 5, extension 114 is a track interface that fits in thetrack or channel 122 defined by spring guide 112, which here also actsas a guide for planar surface 106. However, different configurations maybe designed where extension 114 fits in a separate guide, or is guidedby the surfaces of support member 104. In this exemplary embodiment,extension 114 is circular, and fits in channel 122 on top of spring 110.Thus, the force exerted by spring 110 is transmitted to planar surface106 through the extensions 114, which have the dual role of interfacingwith springs 110 and keeping the planar surface 106 within the guideportions. Extension 114 may enter channel 122, for example, through theopening defined by edges 120. The combination of forces applied to aplurality of extensions 114 by corresponding spring guides 112 maintainsplanar surface 106 in its proper position relative to base 102,particularly if extensions 114 are spaced around the perimeter of planarsurface 106, as shown in FIG. 3.

[0030] According to an exemplary embodiment of the present invention,the frame of cradle 100 is disassembled, so that when not in use thecradle 100 may be stored or transported easily. In the presentembodiment, planar surface 106 may be lifted up away from supportmembers 104, since during use it rests by gravity on springs 110, withinspring guides 112. Springs 110 also can be lifted out of spring guides112, which in turn are easily removable from support members 104.Support members 104 may be removed from base 102, since they are held inplace thereon by a friction or locking mechanism. In an alternativeembodiment, support members 104 may be hinged to base 102, so that whennot in use they may be folded within the base 102.

[0031]FIG. 6 shows an exemplary embodiment of the mounting blocks 152for the support members 104 and springs 110 to base 102. A singlemounting block 152 may be used for both components, or separateattachments may be used. The mounting block 152 may be a solidcylindrical base having a shape, e.g., of a male pedestal. The supportmember 104 and the spring 110 may be removably coupled to the mountingblock 152.

[0032] In alternative exemplary embodiment of the present invention, thesupport member 104 and the spring 110 may be attached to the base 102using a female attaching members 240 shown in FIG. 3a. Each of thefemale attaching members 240 is coupled on the exterior of the base 102and has a shape of a female coupling. The support member 104 and thespring 110 are removably inserted into the female attaching member 240.The guide 112 stops at the top of the base 102, while the spring 110extends through the base 102 and stops at the bottom of the base 102.The female attaching members 240 also server buffers to preventincidental damage to the cradle 100 if it collides with another object.

[0033] As indicated above, cradle 100 may be folded when not in use.FIGS. 7 and 8 show successive steps to disassemble and fold the cradle100. In FIG. 7, the springs 110 and support members 104 are removed frommounting blocks 152 of base 102, and are placed within a box likestorage portion formed by bottom surface 150 and side surfaces 154 ofbase 102. In a subsequent step illustrated in FIG. 8, the planar surface106 is placed on top of the springs 110 and support members 104, forminga lid to the box defined by base 102. In another embodiment, latches orlocks may be used to prevent separation of planar surface 106 from base102, so that the components of the support mechanism may be securelyheld in the box like structure. The entire cradle 100 can be transportedbetween job sites, or may be stored while occupying a minimal amount ofspace.

[0034] This dual nature of the cradle 100 is one of its main advantages.The cradle 100 may, on one hand, serve to support materials 200 at acertain height; on the another hand, the cradle 100, when in the foldedposition, may server a dolly to move the materials 200. Anotheradvantage of the present invention is that the cradle 100 does notrequire any complicated electrical and/or mechanical components.Furthermore, the cradle 100 allows to load the materials 200 from thetop.

[0035] In the preceding specification, the present invention has beendescribed with reference to specific exemplary embodiments thereof. Itwill, however, be evident that various modifications and changes may bemade thereto without departing from the broadest spirit and scope of thepresent invention as set forth in the claims that follow. Thespecification and drawings are accordingly to be regarded in anillustrative rather than restrictive sense.

What is claimed is:
 1. A portable cradle, comprising: a removable planarsurface; a base; and a plurality of vertical support members removablycoupled to the base and supporting the planar surface above the base,each support member including a biasing member urging the planar memberupward away from the base with a total biasing force applied to theplanar member being selected based on property of materials to besupported on the planar surface so that a position of an upper surfaceof the supported materials remains substantially constant as a quantityof materials supported on the planar surface is changed.
 2. The portablecradle according to claim 1, wherein each of the support members issubstantially perpendicular to the base.
 3. The portable cradleaccording to claim 1, wherein the base includes a storage portion whichaccommodates the removable planar surface and the support members in adisassembled configuration.
 4. The portable cradle according to claim 1,wherein the biasing member includes a spring and a guide.
 5. Theportable cradle according to claim 4, wherein the spring is a coilspring.
 6. The portable cradle according to claim 1, wherein each of thesupport members is disposed at a corresponding corner of the base. 7.The portable cradle according to claim 4, wherein the guide defines aninternal channel for the spring designed to limit movement of the springin directions perpendicular to a longitudinal axis of the channel. 8.The portable cradle according to claim 4, wherein the guide includes astructural portion adapted to prevent buckling of the guide.
 9. Theportable cradle according to claim 4, wherein the removable planarsurface is detachably attached to the spring.
 10. The portable cradleaccording to claim 9, wherein the removable planar surface hasextensions slidably fitting in the guide, allowing movement of theplanar surface along the guide.
 11. The portable cradle according toclaim 4, wherein the base is detachable attached to the springs.
 12. Theportable cradle according to claim 1, wherein the biasing memberincludes: a spring guide detachably attached to the base, the springguide extending in a direction of movement of the planar surface; and aspring disposed in the spring guides, the springs providing a restoringforce in the direction of movement, wherein the springs are attached atone end to the planar surface.
 13. The portable cradle according toclaim 12, wherein each of the plurality of spring guides issubstantially perpendicular to the base.
 14. The portable cradleaccording to claim 1, wherein the base and the planar surface areadapted to form sides of a box when the support members are in thedisassembled configuration, and wherein the support members fit in thebox.
 15. The portable cradle according to claim 1, wherein the biasingmember resists displacement of the planar surface with a forceproportional to the displacement.
 16. The portable cradle according toclaim 1, wherein the support members are storable in a chamber formed bythe base and the planar surface.
 17. The portable cradle according toclaim 1, further comprising: a plurality of moving arrangements coupledto the base.
 18. The portable cradle according to claim 17, wherein eachof the moving arrangements is a wheel having a braking mechanism andwherein, when the braking mechanism is engaged, it prevent the cradlefrom moving.
 19. The portable cradle according to claim 1, wherein thematerials are loaded onto the cradle by being placed on a top of theplanar surface.